The internet resources especially devices use Internet Protocol (IP) addresses which are unique for communication purposes. There are two major IP addressing schemes; Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv4). Most devices on the internet have been using the IPv4 for a long time. And since the internet grows exponentially according to the number of users, IPv4 addresses are nearly maxed out. It is this problem that led to the development of another upgraded version, the IPv6.
就容量而言，IPv4 的长度为 32 位，相当于约 43 亿个 IP 地址。另一方面，IPv6 的长度为 128 位，约为 3.4×10^38 个 IP 地址，超过一万亿个。有了这样的容量，用 IPv6 取代 IPv4 方案就顺理成章了。
为什么要禁用它？
与 IPv4 相比，IPv6 有很多优点，但由于其他因素，最好还是继续使用 IPv4 寻址方案。以下是你应该禁用它的原因，尤其是在使用 VPN 时；
IP 泄露
Most VPN service providers do not fully support the IPv6 addressing scheme, but they are compatible with IPv4. When tunneling occurs, data traffic using IPv4 will rarely leak as compared to IPv6. Due to incompatibility issues, data traffic using IPv6 will bypass the VPN tunnel and will be serviced directly by the ISP. This, in turn, will make you public to prying eyes including your ISP hence a leak.
除泄漏外，还有其他原因导致您应该禁用它；
硬件不兼容
Most current internet-based hardware such as firewalls don’t fully support IPv6 while some servers support the addressing. This incompatibility has given rise to vulnerabilities which some malware has exploited. For instance, the most recent widespread malware that used command and control servers were IPv6 based. This gave them the advantage to bypass most firewalls that were only blocking IPv4 internet traffic.
配置问题
IPv6 is different from IPv4, and most people know how to configure IPv4 than IPv6. A transition from IPv4 to IPv6 can cause mistakes and confusions which can make it hard to troubleshoot network entities. Since also IPv6 hasn’t been adopted much, tunneling IPv6 over IPv4 has also led to security gaps not only in VPNs but also in other networks in general.
如何了解网络是否正在使用 IPv6
This is a simple way to know as it involves typing this URL http://ip6.nl/ in your browser. The page will finish loading with both IPv4 and IPv6 results. If it says no IPv6 connectivity, you are safe.
如何在 Windows 10 中禁用 IPv6
步骤 1.右键单击任务栏上的网络图标，然后单击 "打开网络和共享中心"。
第 2 步在打开的设置窗口中，点击更改适配器设置/选项
第 3 步右键单击活动网络适配器（根据连接情况，可以是WIFI或以太网），然后选择 "属性"。
第 4 步打开属性窗口后，滚动找到Internet 协议版本 6 (TCP/IPv6)。取消勾选 旁边的复选框，然后单击 "确定 "保存更改。
步骤 5.现在重启电脑，尽情使用 VPN，避免 IPv6 泄露。
